The existing communication system is mainly the GSM network and CDMA network; and the coexistence of the GSM and CDMA absolutely introduces the GSM-CDMA (GC) intercommunication which means that a GSM subscriber sends a message to a CDMA subscriber or a CDMA subscriber sends a message to a GSM subscriber.
In order to process the GC intercommunication message well, it is necessary to forward a GSM message from a GSM short message service center to a CDMA short message service center, and vice versa. Because of the different protocols of the GSM and the CDMA, the message needs to be converted.
At present, the GC intercommunication message is forwarded by an intercommunication gateway in China, i.e., a short message service center converts an intercommunication message into an opened Short Message Peer to Peer (SMPP) message and then forwards it to an intercommunication gateway, and the intercommunication gateway submits the SMPP message to another short message service center which converts the SMPP message into a corresponding message for processing.
However, internationally, in consideration of charging and the like, operators do not recognize the intercommunication way through the SMPP and require that the GC intercommunication message should be forwarded via the NO. 7 signaling, that is, be forwarded by the GC signaling gateway. At present, the GC signaling gateway is implemented by a front-end processor and firstly requires that a front-end processor module should support both the GSM and CDMA protocols as well as the conversion between a GSM message and a CDMA message. The GSM network identifies a subscriber by the International Mobile Subscriber Identifier (IMSI), while the CDMA network identifies a subscriber by the IMSI or the Mobile Identification Number (MIN), so, if the CDMA network adopts the MIN, the front-end processor needs to convert the MIN into the IMSI. If it is required to support number portability, the front-end processor needs to set Global Translation (GT) in different formats according to the home of the target number. It can be seen from above that the GC signaling gateway implemented by the front-end processor is complex to process and also inconvenient to process due to the limited system resources of the front-end processor.